511 research outputs found
Cataclysmic Variables from USNO-B1.0 Catalog: Stars with Outbursts on Infrared Palomar Plates
The search was performed for cataclysmic variable stars with outlying
infrared magnitudes in USNO-B1.0 catalog. The selection was limited to objects
in the Northern hemisphere with (B1-R1) 3.5. The search method
is described, and the details on individual stars are given. In total 27
variable objects were found with 20 being the previously known ones and 7 - new
discoveries. 4 of newly found variables are dwarf novae, while the remaining 3
- pulsating red variables of Mira or semi-regular types, including a heavily
reddened one in Pelican nebula. The correct pulsation period is determined for
two stars discovered by other researchers, and the dwarf nova nature is
confirmed for another object previously suspected as such. The perspectives of
the proposed search technique in the framework of Virtual Observatory are also
discussed.Comment: 8 pages, 10 figures, submitted to Astronomy Letter
QZ Serpentis: A Dwarf Nova with a 2-Hour Orbital Period and an Anomalously Hot, Bright Secondary Star
We present spectroscopy and time-series photometry of the dwarf nova QZ Ser.
The spectrum shows a rich absorption line spectrum of type K4 +- 2. K-type
secondary stars are generally seen in dwarf novae with orbital periods P-orb
around 6 h, but in QZ Ser the absorption radial velocities show an obvious
modulation (semi-amplitude 207(5) km/s) at P-orb = 119.752(2) min, much shorter
than typical for such a relatively warm and prominent secondary spectrum. The
H-alpha emission-line velocity is modulated at the same period and roughly
opposite phase. Time-series photometry shows flickering superposed on a
modulation with two humps per orbit, consistent with ellipsoidal variation of
the secondary's light. QZ Ser is a second example of a relatively short-period
dwarf nova with a surprisingly warm secondary. Model calculations suggest that
the secondary is strongly enhanced in helium, and had already undergone
significant nuclear evolution when mass transfer began. Several sodium
absorption features in the secondary spectrum are unusually strong, which may
indicate that the present-day surface was the site of CNO-cycle hydrogen
burning in the past.Comment: 11 pages, 3 postscript figures, 1 jpeg greyscale figure. Accepted for
publication in PAS
Identification of new cataclysmic variables in the 1RXS and USNO-B1.0 catalogs
As a result of applying the original optical variability search method on
publicly available data, we have found eight new cataclysmic variables and two
possible Optically Violent Variable quasars among the previously unidentified
X-ray sources in the ROSAT catalog. We describe the search method and present
the characteristics of the newly identified variable stars. The obtained
results demonstrate the large potential of the concept of Virtual Observatory
for identifying new objects of astrophysical interest.Comment: 16 pages, 11 figures, 2 tables; submitted to Astronomy Letter
Spectrophotometric determination of phenolic compounds sum in plants using aluminum chloride, 18-molybdodiphosphate and Folin-Ciocalteu reagents
ΠΠ° ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠΈ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² Π°Π½Π°Π»ΠΈΠ·Π° ΡΡΠ΄Π° Π»Π΅ΠΊΠ°ΡΡΡΠ²Π΅Π½Π½ΡΡ
ΠΏΡΠ΅ΠΏΠ°ΡΠ°ΡΠΎΠ² Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠ°ΡΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ ΡΡΡΡΡ (ΡΠ°Π±Π»Π΅ΡΠΊΠΈ, Π½Π°ΡΡΠΎΠΉΠΊΠΈ, ΡΠΈΡΠΎΠΏΡ), Π»Π΅ΠΊΠ°ΡΡΡΠ²Π΅Π½Π½ΡΡ
ΡΠ°ΡΡΠ΅Π½ΠΈΠΉ, ΡΡΡΠΊΡΠΎΠ², ΡΠ°Π΅Π² ΠΈ Ρ.ΠΏ. ΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ 18-ΠΌΠΎΠ»ΠΈΠ±Π΄ΠΎΡΠΎΡΡΠΎΡΠ½ΡΠΉ ΠΠΠ ΡΡΡΡΠΊΡΡΡΡ ΠΠΎΡΡΠΎΠ½Π° (18-ΠΠ€Π), ΠΊΠ°ΠΊ ΠΈ ΡΠ΅Π°ΠΊΡΠΈΠ² Π€ΠΎΠ»ΠΈΠ½Π°-Π§ΠΎΠΊΠ°Π»ΡΡΠ΅Ρ (Π€Π§), ΠΏΡΠΈΠ³ΠΎΠ΄Π΅Π½ Π΄Π»Ρ ΡΠΏΠ΅ΠΊΡΡΠΎΡΠΎΡΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΡΠΌΠΌΡ ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ. ΠΡΠΎΡ Π²ΡΠ²ΠΎΠ΄ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠΆΠ΄Π°Π΅ΡΡΡ Π²ΡΡΠΎΠΊΠΎΠΉ ΡΡΠ΅ΠΏΠ΅Π½ΡΡ ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΈ ( R Β² > 0.95) ΠΌΠ΅ΠΆΠ΄Ρ Π΄Π°Π½Π½ΡΠΌΠΈ, ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΠΌΠΈ Π΄Π²ΡΠΌΡ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ°ΠΌΠΈ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ Π°Π½Π°Π»ΠΈΠ·Π° ΠΎΠ±Π΅ΠΈΠΌΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ°ΠΌΠΈ Π²ΠΎ ΠΌΠ½ΠΎΠ³ΠΈΡ
ΡΠ»ΡΡΠ°ΡΡ
ΠΏΡΠ°ΠΊΡΠΈΡΠ΅ΡΠΊΠΈ Π½Π΅ ΠΎΡΠ»ΠΈΡΠ°ΡΡΡΡ ΠΏΠΎ Π°Π±ΡΠΎΠ»ΡΡΠ½ΠΎΠΉ Π²Π΅Π»ΠΈΡΠΈΠ½Π΅, ΡΡΠΎ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΠ΅Ρ ΠΎ Π±Π»ΠΈΠ·ΠΎΡΡΠΈ ΠΊΠ°ΠΆΡΡΠΈΡ
ΡΡ ΠΌΠΎΠ»ΡΡΠ½ΡΡ
ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠΎΠ², ΡΠ°ΡΡΡΠΈΡΠ°Π½Π½ΡΡ
Π΄Π»Ρ ΡΠ΅Π°ΠΊΡΠΈΠΉ ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ Ρ ΡΠΊΠ°Π·Π°Π½Π½ΡΠΌΠΈ ΡΠ΅Π°Π³Π΅Π½ΡΠ°ΠΌΠΈ. Π ΡΠ»ΡΡΠ°Π΅, Π΅ΡΠ»ΠΈ ΠΎΠ±ΡΠ΅Π΅ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ ΠΏΠΎΠ»ΠΈΡΠ΅Π½ΠΎΠ»ΠΎΠ² ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΠ΅ΡΡΡ ΠΏΡΠΈΡΡΡΡΡΠ²ΠΈΠ΅ΠΌ ΡΠ»Π°Π²ΠΎΠ½ΠΎΠ»ΠΎΠ² ΠΈΠ»ΠΈ ΠΎΠΊΡΠΈΠΊΠΎΡΠΈΡΠ½ΡΡ
ΠΊΠΈΡΠ»ΠΎΡ, ΡΠΎ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΏΠΎΡΠ»Π΅Π΄Π½ΠΈΡ
Ρ 18-ΠΠ€Π ΡΠ²Π»ΡΠ΅ΡΡΡ Π±ΡΡΡΡΡΠΌ ΠΈ ΠΏΠΎΠ»Π½ΡΠΌ ΠΏΡΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠΈ ΡΠ΅Π°ΠΊΡΠΈΠΈ ΠΏΡΠΈ ΡΠ = 7.4. ΠΠ»Ρ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΌΠ΅Π½Π΅Π΅ ΡΠ΅Π°ΠΊΡΠΈΠΎΠ½Π½ΠΎΡΠΏΠΎΡΠΎΠ±Π½ΡΡ
ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ (ΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΠ½ΡΠ΅ ΠΏΠΎΠ»ΠΈΡΠ΅Π½ΠΎΠ»Ρ, ΠΊΠ°ΡΠ΅Ρ
ΠΈΠ½Ρ, ΠΎΠΊΡΠΈΠ±Π΅Π½Π·ΠΎΠΉΠ½ΡΠ΅ ΠΊΠΈΡΠ»ΠΎΡΡ) ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠ±Π»Π°ΡΡΡ ΡΠ Π²ΡΡΠ΅ 9.0. ΠΠΎΡΡΠ΅Π»ΡΡΠΈΡ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠΎΠ² ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΡΠΌΠΌΡ ΠΏΠΎΠ»ΠΈΡΠ΅Π½ΠΎΠ»ΠΎΠ², ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ 18-ΠΠ€Π ΠΈΠ»ΠΈ ΡΠ΅Π°ΠΊΡΠΈΠ²Π° Π€Π§, Ρ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ°ΠΌΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠΈ, ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΡΡΠ΅ΠΉ Ρ
Π»ΠΎΡΠΈΠ΄ Π°Π»ΡΠΌΠΈΠ½ΠΈΡ, Π½Π°Π±Π»ΡΠ΄Π°Π΅ΡΡΡ ΡΠΎΠ»ΡΠΊΠΎ Π² ΡΠΎΠΌ ΡΠ»ΡΡΠ°Π΅, Π΅ΡΠ»ΠΈ Π² ΡΠ°ΡΡΠ΅Π½ΠΈΡΡ
ΠΏΡΠ΅ΠΎΠ±Π»Π°Π΄Π°ΡΡ ΡΠ»Π°Π²ΠΎΠ½Ρ, ΠΈΠΌΠ΅ΡΡΠΈΠ΅ Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠ»ΡΠ½ΡΠ΅ Π³ΡΡΠΏΠΏΡ Π² ΠΏΠΎΠ»ΠΎΠΆΠ΅Π½ΠΈΠΈ 3 ΠΈ/ΠΈΠ»ΠΈ 5.It was concluded from the results of the analysis of a number of drugs on the basis of vegetable raw materials such as tablets, tinctures, syrups, medicinal plants, fruits, teas, etc., that 18-molybdodiphosphate heteropoly anion (18-MPA) and Folin-Ciocalteu (FCR) reagents were suitable for the spectrophotometric determination of the total content of phenolic compounds. This conclusion was confirmed by a high degree of correlation ( R Β² > 0,95) between the results obtained by the two methods. In many cases, the absolute difference between the results of both methods was low, and that was an evidence of closeness of apparent molar absorptivity values calculated for the reactions with the above mentioned reagents. Interaction of polyphenols with 18-MPA at pH 7.4 was rapid and complete when the total content of polyphenols was determined by the presence of flavonols or cinnamic acids. Range of pH > 9.0 was optimal for the determination of less reactive compounds (polymeric polyphenols, catechins, oxybenzoic acids). The results of the polyphenols sum determination obtained with 18-MPA or FCR reagents correlated with the results obtained using the aluminium chloride method only in the case when flavons with hydroxy groups in the positions 3 and/or 5 were dominating phenol species present in the plants
Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8
We report on the MASTER Global Robotic Net discovery of an eclipsing binary,
MASTER OT J095310.04+335352.8, previously known as unremarkable star TYC
2505-672-1, which displays extreme orbital parameters. The orbital period
P=69.1 yr is more than 2.5 times longer than that of epsilon-Aurigae, which is
the previous record holder. The light curve is characterized by an extremely
deep total eclipse with a depth of more than 4.5 mag, which is symmetrically
shaped and has a total duration of 3.5 yrs. The eclipse is essentially gray.
The spectra acquired with the Russian 6 m BTA telescope both at minimum and
maximum light mainly correspond to an M0-1III--type red giant, but the spectra
taken at the bottom of eclipse show small traces of a sufficiently hot source.
The observed properties of this system can be better explained as the red giant
eclipsed by a large cloud (the disk) of small particles surrounding the
invisible secondary companion.Comment: 8 figures, 9 pages, Astronomy and astrophysics in prin
Reaction features of 18-molibdodiphosphate and Folin-Ciocalteu reagent with phenolic compounds
Π‘ΡΠ°Π²Π½ΠΈΡΠ΅Π»ΡΠ½ΠΎΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠ΅Π°ΠΊΡΠΈΠΈ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΡ 18-ΠΌΠΎΠ»ΠΈΠ±Π΄ΠΎΡΠΎΡΡΠΎΡΠ½ΠΎΠ³ΠΎ Π³Π΅ΡΠ΅ΡΠΎΠΏΠΎΠ»ΠΈΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° (18-ΠΠ€Π) ΠΈ ΡΠ΅Π°ΠΊΡΠΈΠ²Π° Π€ΠΎΠ»ΠΈΠ½Π°-Π§ΠΎΠΊΠ°Π»ΡΡΠ΅Ρ (Π€Π§) Ρ ΡΡΠ΄ΠΎΠΌ ΠΏΡΠ΅Π΄ΡΡΠ°Π²ΠΈΡΠ΅Π»Π΅ΠΉ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΊΠ»Π°ΡΡΠΎΠ² ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ ΡΠ²ΠΈΠ΄Π΅ΡΠ΅Π»ΡΡΡΠ²ΡΠ΅Ρ ΠΎ Π±Π»ΠΈΠ·ΠΎΡΡΠΈ ΡΠ΅Π°ΠΊΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡΠΈ ΠΎΠ±ΠΎΠΈΡ
ΡΠ΅Π°Π³Π΅Π½ΡΠΎΠ², ΡΡΠΎ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°ΡΡ 18-ΠΠ€Π, Π½Π°ΡΡΠ΄Ρ Ρ ΡΠ΅Π°ΠΊΡΠΈΠ²ΠΎΠΌ Π€Π§, Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΎΠ±ΡΠ΅Π³ΠΎ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΡ ΡΠ΅Π½ΠΎΠ»ΠΎΠ². Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ 18-ΠΠ€Π ΡΠ²Π»ΡΠ΅ΡΡΡ Π±ΠΎΠ»Π΅Π΅ Π°ΠΊΡΠΈΠ²Π½ΡΠΌ ΠΎΠΊΠΈΡΠ»ΠΈΡΠ΅Π»Π΅ΠΌ ΠΏΠΎ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΊ ΡΠ΅Π½ΠΎΠ»Π°ΠΌ, Π²ΡΠ»Π΅Π΄ΡΡΠ²ΠΈΠ΅ ΡΠ΅Π³ΠΎ Π² ΡΡΠ°Π²Π½Π΅Π½ΠΈΠΈ Ρ ΡΠ΅Π°ΠΊΡΠΈΠ²ΠΎΠΌ Π€Π§ ΠΈΠ½ΡΠ΅ΡΠ²Π°Π» ΠΎΠΏΡΠΈΠΌΠ°Π»ΡΠ½ΡΡ
Π·Π½Π°ΡΠ΅Π½ΠΈΠΉ ΡΠ ΡΠ΄Π²ΠΈΠ½ΡΡ Π² Π±ΠΎΠ»Π΅Π΅ ΠΊΠΈΡΠ»ΡΡ ΠΎΠ±Π»Π°ΡΡΡ, ΡΠΊΠΎΡΠΎΡΡΡ ΡΠ΅Π°ΠΊΡΠΈΠΈ Π²ΡΡΠ΅, Π° ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΠ΅ΠΌΠ°Ρ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡ ΡΠ΅Π°Π³Π΅Π½ΡΠ° Π½Π° ΠΏΠΎΡΡΠ΄ΠΎΠΊ ΠΌΠ΅Π½ΡΡΠ΅. ΠΠ±Π½Π°ΡΡΠΆΠ΅Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠΈ ΠΎΠ±ΠΎΠΈΡ
ΡΠ΅Π°ΠΊΡΠΈΠ²ΠΎΠ² ΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΠΈ ΠΎΠΏΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ»ΠΎΡΠ½ΠΎΡΡΠΈ Π² ΠΌΠ°ΠΊΡΠΈΠΌΡΠΌΠ΅ ΠΏΠΎΠ³Π»ΠΎΡΠ΅Π½ΠΈΡ Π³Π΅ΡΠ΅ΡΠΎΠΏΠΎΠ»ΠΈΡΠΈΠ½ΠΈ (ΠΠΠ‘) Π³ΡΠ°Π΄ΡΠΈΡΠΎΠ²ΠΎΡΠ½ΡΠ΅ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΡΠ²Π»ΡΡΡΡΡ Π½Π΅Π»ΠΈΠ½Π΅ΠΉΠ½ΡΠΌΠΈ. ΠΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΠΉ ΠΏΡΠΈΡΠΈΠ½ΠΎΠΉ ΡΡΠΎΠ³ΠΎ ΡΠ»ΡΠΆΠΈΡ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ ΡΠΎΡΡΠ°Π²Π° ΠΈ Π³Π»ΡΠ±ΠΈΠ½Ρ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ Π³Π΅ΡΠ΅ΡΠΎΠΏΠΎΠ»ΠΈΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° (ΠΠΠ) ΠΏΡΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΈ ΡΠΎΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΠΠ : ΡΠ΅Π½ΠΎΠ». Π ΡΠΏΠ΅ΠΊΡΡΠ°Ρ
ΠΠΠ‘, ΠΏΠΎΠ»ΡΡΠ°Π΅ΠΌΡΡ
ΠΏΡΠΈ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΠΈ 18-ΠΠ€Π, ΠΈΠΌΠ΅Π΅ΡΡΡ ΠΈΠ·ΠΎΠ±Π΅ΡΡΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΠΎΡΠΊΠ° (Ξ» = 900 Π½ΠΌ), ΡΡΠΎ ΠΏΠΎΠ·Π²ΠΎΠ»ΠΈΠ»ΠΎ ΠΏΠΎΠ»ΡΡΠ°ΡΡ ΡΡΡΠΎΠ³ΠΎ ΠΏΡΡΠΌΠΎΠ»ΠΈΠ½Π΅ΠΉΠ½ΡΠ΅ Π³ΡΠ°Π΄ΡΠΈΡΠΎΠ²ΠΎΡΠ½ΡΠ΅ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ. ΠΡΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠΈ 18-ΠΠ€Π Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π²ΠΎΡΡΡΠ°Π½Π°Π²Π»ΠΈΠ²Π°ΡΡΠΈΡ
ΡΠ°Ρ
Π°ΡΠΎΠ², ΠΏΡΠΎΡΡΡΡ
ΡΠ΅Π½ΠΎΠ»ΠΎΠ², ΡΡΠ»ΡΡΠΈΡ-ΠΈΠΎΠ½ΠΎΠ², Π²ΠΈΡΠ°ΠΌΠΈΠ½ΠΎΠ² ΠΈ Π½Π΅ΠΊΠΎΡΠΎΡΡΡ
Π΄ΡΡΠ³ΠΈΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ Π½Π° ΡΠ΅Π·ΡΠ»ΡΡΠ°Ρ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΠ΅Π½ΠΎΠ»ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ ΡΡΠ°Π½ΠΎΠ²ΠΈΡΡΡ Π½Π°ΠΌΠ½ΠΎΠ³ΠΎ ΠΌΠ΅Π½ΡΡΠΈΠΌ. ΠΠ° ΠΏΡΠΈΠΌΠ΅ΡΠ΅ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΡΡΡΠΈΠ½Π° ΠΈ Π°ΡΠΊΠΎΡΠ±ΠΈΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ ΠΏΡΠΈ ΡΠΎΠ²ΠΌΠ΅ΡΡΠ½ΠΎΠΌ ΠΏΡΠΈΡΡΡΡΡΠ²ΠΈΠΈ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΡΠΎΠ»ΡΠΊΠΎ ΠΏΡΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠΈ 18-ΠΠ€Π ΡΠ΄Π°Π΅ΡΡΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΡΡ ΡΠ°Π·Π΄Π΅Π»ΡΠ½ΠΎ Π² ΡΠΌΠ΅ΡΠΈ ΡΠ΅Π½ΠΎΠ» ΠΈ Π±ΠΎΠ»Π΅Π΅ Π°ΠΊΡΠΈΠ²Π½ΡΠΉ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²ΠΈΡΠ΅Π»Ρ ΠΏΡΡΠ΅ΠΌ Π²Π°ΡΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ.The comparative investigation of a reaction between 18-molybdophosphate heteropoly complex (18-MPC) and Folin-Ciocalteu reagent (FCR) with a diversity of the representatives of different phenolic compounds classes shows a similar reaction behavior for both reagents. This evidence can be used for the application of 18-MPC along with FCR for the evaluation of total content of phenols. It was established that 18-MPC is more active as an oxidizing agent with respect to phenols and for this reason in comparison with FCR the range of optimal values of pH is displaced into the more acidic region, the reaction rate is higher, and the concentration of the reagent is one order of magnitude less. It was also discovered that by using both reagents and measuring the absorbance in absorption maximum of heteropoly blue (HPB), the graduation curves were nonlinear. The observed phenomenon was explained by the changes in the composition and depth of the HPB reduction occurring when changing the ratio between the heteropoly complex and the phenol. The isobestic point present in the absorption spectra of HPBs and which was acquired from 18-MPC allows obtaining strictly linear calibration curves. By using 18-MPC the influence of reducing sugars, simple monophenols, sulphite ions, vitamins and some other compounds on the result of the determination of phenolic compounds becomes much smaller. It was shown by example of the ascorbic acid and rutin determination in the mixture that only by using 18-MPC it was possible to determine phenol and more active reducing agent separately by varying the pH of the determination
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